NOTICE: This version of the NSF Unidata web site (archive.unidata.ucar.edu) is no longer being updated.
Current content can be found at unidata.ucar.edu.

To learn about what's going on, see About the Archive Site.

Re: [netcdfgroup] Creating a NetCDF file for VisIt with an unstructured grid

Tim,
VisIt works very well with HDF5 formatted files. One question, is do you want a 3D image or a 2D image? If you want a 3D image, there is a format called VizSchema that might work for what you want. You can see the format here. 
https://ice.txcorp.com/trac/vizschema/wiki

  Ciao,
  Dave


Dave Kindig
Research Assistant - TechX Corp (www.txcorp.com)
303-444-2386


On 03/27/2012 08:50 AM, Tim Duly wrote:

Rich,
Thank you for the information. My data comes from an unformatted Fortran file, and Python was the easiest way to read this data. I'd prefer to use VisIt as I'd like to extend this project with a 2D plot with time, and then to a 3D plot with time.
Perhaps I wasn't clear enough-- I have all the data read into Python right now, but am having trouble writing the coordinate information into the NetCDF. I am able to get the actual data into VisIt, but it's not "applied" to the (200 x 100) matrix X and Y coordinate information.
From my research, it doesn't look like NetCDF is able to do this. Perhaps I should be using another data format for VisIt? 

Thanks,
Tim
On Tue, Mar 27, 2012 at 9:20 AM, Rich Signell <rsignell@xxxxxxxx <mailto:rsignell@xxxxxxxx>> wrote: 

    Tim,

    You mention quite a few things here: unstructured grids, Matlab,
    NetCDF, CF, Python and Visit.

    If your goal is to truly to visualize unstructured grid data from
    NetCDF files (or OPeNDAP datasets) using Python, take a look at this
    screen shot using Mayavi2

    http://dl.dropbox.com/u/12710282/Screenshot-Mayavi.png

    and the simple code that produced it:

    http://dl.dropbox.com/u/12710282/triangular_mesh_demo.py

    Mayavi2 comes with at least two scientific Python distributions:
    Python(x,y) (free, works on 32 bit windows) and the Enthought Python
    Distribution (free for educational use, works on 32/64 bit windows,
    mac and linux).  You should be able to run the above python script
    without changes on either distribution.

    However, it sounds like you actually have structured grid data in a
    text file that you want to use.   In python, I would use numpy
    "genfromtxt" to read from the text file, and visualize with Mayavi2's
    "surf" function.  See:
    http://github.enthought.com/mayavi/mayavi/auto/examples.html

    If you want to save your data in a NetCDF file, I'd use the
    NetCDF4Python package (also included in the above scientific python
    distributions).   This would allow you to visualize it in other tools
    as well, like Unidata's IDV.

    Good Luck,
    -Rich

    On Mon, Mar 26, 2012 at 3:31 PM, Tim Duly <duly2@xxxxxxxxxxxx
    <mailto:duly2@xxxxxxxxxxxx>> wrote:
    > Hello,
    >
    > I have a relatively simple task. I have 2D data, of dimension
    200x100 that
    > belong to an unstructured grid that contains X and Y, both of
    which are
    > dimension 200x100.  In other words, I have DATA = f(X,Y).
    >
    > I'm trying to plot this in VisIt, but am having a tough time
    applying the
    > unstructured grid to the actually data.  In MATLAB, for example,
    this is
    > easily accomplished with surf(X,Y,DATA), but I'm having
    difficulties finding
    > the equivalent in NetCDF.  How do I do this?  Is this problem
    solved in
    > NetCDF or in VisIt?
    >
    > I am using the Python library NetCDF to transform unformatted
    Fortran data
    > into NetCDF format.  I have read this page
    > (
    
http://cf-pcmdi.llnl.gov/documents/cf-conventions/1.4/cf-conventions.html#id2984605
 )
    > but I do not understand how to do this with the NetCDF library
    in python.
    >  Should I use another data format besides NetCDF?
    >
    > Any help would be greatly appreciated.
    >
    > Thanks,
    > Tim
    >
    > _______________________________________________
    > netcdfgroup mailing list
    > netcdfgroup@xxxxxxxxxxxxxxxx <mailto:netcdfgroup@xxxxxxxxxxxxxxxx>
    > For list information or to unsubscribe,  visit:
    > http://www.unidata.ucar.edu/mailing_lists/



    --
    Dr. Richard P. Signell (508) 457-2229 <tel:%28508%29%20457-2229>
    USGS, 384 Woods Hole Rd.
    Woods Hole, MA 02543-1598




_______________________________________________
netcdfgroup mailing list
netcdfgroup@xxxxxxxxxxxxxxxx
For list information or to unsubscribe,  visit: 
http://www.unidata.ucar.edu/mailing_lists/
  • 2012 messages navigation, sorted by:
    1. Thread
    2. Subject
    3. Author
    4. Date
    5. ↑ Table Of Contents
  • Search the netcdfgroup archives: